Anthropic best model is Sonnet 3.5 in my opinion. The reason its good is it is very effective for the price and fast. (I do think Google has caught up a lot in this regard). However, not having COT makes its results worse than similarly cheap COT based models.

Leaderboards don't care about cost. Leaderboards largely rank a combination of accuracy + speed. Anthropic has fell behind Google in accuracy + speed (again missing COT), and frankly behind Google in raw speed.